6. Stop the reaction by adding 1 ml of 0.5 M
EDTA or by heating heating to 95-100 °C for a couple of minutes.

7. Immediately before use in hybridization, denature the labeled DNA
by heating to 95-100 °C for 5 minutes and then put on ice.
To avoid poping up of the microcentrifuge tube, puncture a small hole
on the cap using a needle or use a microcentrifuge tube cap lock.